Preliminary EPR spectra of VO and Tempol bound to dendrimers used for drug and contrast agent delivery have shown significant dependence on temperature. In order to extract more precise rotational correlation times or ranges of times, computer simulations must be carried out. First proper spectral parameters from the slow and fast motion limits are determined. These parameters are then used to correctly assign dynamical parameters. Simulation programs have been corrected and improved. Anisotropic rotational models and jump diffusion models are also used.